DE60036334T2 - Fibrous substrate for artificial leather and synthetic leather that uses it - Google Patents

Description

The The present invention relates to a fibrous substrate for artificial leather, which feels less rubbery and less repellent than conventional ones Imitation leather, extremely dense feels and a texture like soft natural leather having.

At present becomes Synthetic leather generally made by a process which the impregnation a nonwoven fabric comprising fibers (referred to as microfine fiber-forming fibers) Fibers) made of a non-elastic polymer such as Nylon or polyester are combined and with a solution of a elastic polymer, mainly Polyurethane, in an amount of 15-60% by weight of the nonwoven fabric, microfine Produce fibers by the wet or wet polymer Drying process is solidified and then bundles of microfine fibers microfine fiber-forming fibers or a similar process. According to this Method is the elastic polymer with which the fabric is impregnated solidified into a sponge or block form to form a structure wherein the solidified elastic polymer covers the microfine fiber bundles and envelops. That's why it feels the resulting synthetic leather is very rubbery and repellent what is inherent in the elastic polymer and is natural Leather in the palpable Performance characteristics such as texture, drapability and density feeling and surface feel of the surface inferior. Because the elastic polymer is used in a solvent system The manufacturing steps are like solvent recovery complicated so that the productivity is bad. In many cases the solvent unhealthy for the human body. Thus, the above-mentioned method is involved in environmental issues during manufacturing.

by the way is natural Leather composed only of fibers and has a structure in the few hundred very fine collagen microfibres are bundled into a fiber (about 0.05-1.0 denier (0.05-1.11 dtex)); from a few fibers up a few tens of fibers make up a fiber bundle (1-10 denier (1.11-11.11 dtex)); and the microfibers, fibers or fiber bundles are three-dimensional and densely entwined. For artificial leather Many experiments are also proposed to provide a texture, sense of density and a Obtain appearance that is very similar to the natural one Leather are, using a fibrous substrate, which is composed only of fibers, wherein a fibrous elastic Polymer is used as a binder.

For example, reveal JP-A-59-211664 . 59-211666 . 60-45656 . 60-139879 . 63-12744 . 64-52872 and 2-14056 A process for producing a leather-like sheet by blending sea-island microfine fiber-forming fibers whose island component is an elastic polymer with non-elastic fibers to make a nonwoven fabric, and then removing the sea component of the microfine fibers from the sea Island type to produce elastic microfine fibers. In these processes, portions of the elastic polymer constituting the island component agglutinate with each other to be bundled / combined in the treatment with the solvent during the extraction and removal of the sea components, even if the microfibers comprising the elastic polymer were made sufficiently fine at the stage of microfine fiber-forming fibers. Finally, a single thick fiber is made. For this reason, the fineness of the industrially-made elastic polymer exceeds 2 deniers (2.22 dtex). The elastic polymer and the non-elastic polymer are individually made into fiber bundles, so that only a part of the microfine fibers comprising the non-elastic polymer is bonded to the elastic polymer. Thus, large portions of the fibers comprising the non-elastic polymer are in a loose state. The result is that many of the microfine fibers are unbonded and easily fall out of the leather-like sheeting.

As examples of the fiber form in which an elastic polymer and a non-elastic polymer exist together in a single fiber bundle are disclosed JP-A-61-194247 and 10-37057 A method using core-sheath type composite fibers, wherein the core component is an elastic polymer and the sheath component is a mixed polymer in which a non-elastic polymer in island form in a sea component which is a soluble Polymer is dispersed. JP-A-5-339863 and 5-339864 disclose methods using composite fibers wherein a soluble polymer in which an elastic polymer is dispersed in island form and a soluble polymer in which a non-elastic polymer is dispersed in island form are juxtaposed. According to the former methods, microfibers can be made of the non-elastic polymer. However, the number of strands of fiber comprising the elastic polymer is only one; therefore, the fineness of the industrially-made elastic polymer is a high value above 1 denier (1.11 dtex). According to the latter method, under the dissolution / removal of the soluble component, the elastic polymer agglutinates into thick fibers, so that the fibers feel highly repellent and rubbery. Thus, no artificial leather similar to natural leather can be obtained.

As exceeds that described above the fineness of the fibers comprising the elastic polymer, in all the above mentioned Procedure 1 denier and is too big compared to natural leather. Therefore can not be natural Leather-like Texture are preserved and the density and smoothness of their surface poor.

Examples of the use of composite fibers in which an elastic polymer and a non-elastic polymer are separated are shown in FIG JP-A-62-41375 . 62-78246 . 2-160964 and 6-173173 disclosed. According to these methods, the industrial limits for the fineness of both the fibers comprising the non-elastic polymer and the fibers comprising the elastic polymer are about 0.5 denier (0.5 dtex). The fineness of both the non-elastic fibers obtained and the elastic fibers is greater than that of natural leather. No natural leather-like texture can be expected.

According to all Processes disclosed to date and an elastic polymer in fiber form, is the fineness of the elastic polymer much bigger than that of natural Leather. As a result, texture and appearance are far from those of the natural Leather removed.

As described above, according to the state The technique of making an elastic polymer is not microfiber be so natural Leather-like Texture and appearance can not be achieved. A Object of the present invention is the conversion of an elastic To achieve polymer in microfibers and a fibrous substrate for artificial leather to disposal to make, which feels less rubbery and repellent than Synthetic leather of the prior art, possesses a density feeling and a texture and an appearance like soft natural leather.

Around Synthetic leather with a texture and appearance like natural To obtain leather, investigations were carried out at which of an elastic polymer as island component microfine Fibers are made without agglutination / joining of Dividing the polymer, even if a sea component, e.g. with a solvent extracted and removed. If microfine fibers (A), which comprise an elastic polymer, juxtaposed, agglutinate join them and add while extraction and removal into bundles together. During the However, extraction and removal agglutinate microfine fibers (B), which is a non-elastic Include polymer, not with each other. This fact became one Note received. Thus, a method was tested, the microfine fibers (B) comprising the non-elastic polymer, the microfine fibers (A) comprising the elastic polymer, surrounded to prevent the appearance of parts of the elastic Polymers bundle put together. From microfine fiber-forming fibers in which many microfine fibers (B) comprising the elastic polymer are substantially homogeneous in a sea-component polymer containing many of the dispersed microfines Fibers (A) comprising the elastic polymer are dispersed are, the sea component polymer becomes extracted and with a solvent away. As a result, the elastic polymer becomes microfibers separated to microfine fiber bundles in which the microfine fibers (A), which are the elastic Polymer, and the microfine fibers (B), which is the non-elastic Polymer comprise, mixed together and joined together. Cover in the resulting microfine fibrous substrate and wrap the microfine fibers (B), which are the non-elastic polymer include, the microfine fibers (A), which is the elastic polymer include a finely entwined structure as with natural Leather form, wherein the microfine fibers (B), which the non-elastic polymer, close to the microfine fibers (A), which comprise the elastic polymer with the microfine fibers (A) agglutinate. Thus, the substrate has texture and appearance like natural Leather. As described above, the fact was confirmed that by the production of microfibers made of an elastic polymer a dense and microfine fibrous substrate like natural Leather is made to a leathery cock with texture and appearance like natural leather to surrender. Thus, the present invention has been made.

• (1) das Verhältnis der Anzahl an Strängen aus A zur Anzahl an Strängen aus B in Querschnitten der Bündel (A/B) beträgt 1/5 oder weniger,
• (2) das Verhältnis des Gewichts von A zum Gewicht von B in den Bündeln (A/B) beträgt 10/90 bis 60/40, und
• (3) die mikrofeinen Fasern (B), die das nicht-elastische Polymer umfassen, umschließen jede der mikrofeinen Fasern (A), die das elastische Polymer umfassen.

The present invention relates to a fibrous substrate for artificial leather comprising microfine fiber bundles, each comprising 3 to 50 microfine (A) fibers comprising an elastic polymer and having an average fineness of 0.5 denier (0.5 dtex) or less and 15 or more pieces of microfine fibers (B) comprising a non-elastic polymer and having an average fineness of 0.2 denier (0.2 dtex) or less, the microfine fiber bundles having the following conditions (1 ) to (3):

• (1) the ratio of the number of strands of A to the number of strands of B in cross sections of the bundles (A / B) is 1/5 or less,
• (2) the ratio of the weight of A to the weight of B in the bundles (A / B) is 10/90 to 60/40, and
• (3) the microfine fibers (B) comprising the non-elastic polymer enclose each of the microfine fibers (A) containing the elastic poly include.

The leather-like sheet of the present invention can be obtained by carrying out the following steps (a) - (d):
the step (a) of producing microfine fiber-forming fibers which can be converted into microfine fiber bundles as described above,
the step (b) of producing a fiber-entangled nonwoven fabric comprising the fibers,
the step (c) of removing a sea-component polymer which is a constituent of the fibers to convert the fibers into microfine fiber bundles comprising microfine fibers (A) comprising an elastic polymer (A) [hereinafter referred to as elastic microfine fibers (A) denotes], and microfine fibers (B) comprising a non-elastic polymer (B) [hereinafter referred to as non-elastic microfine fibers (B)], and
the step (d) of roughening at least one surface of the resulting fiber bundles and coloring the resulting wood chip sheet, or applying a resin layer forming a grained surface on at least one surface of the resulting fiber bundles.

Around Synthetic leather with high quality feelability the texture and softness of natural To get leather and surface density feeling is it for present Invention primarily essential that the fibers, which a include non-elastic polymer, are finer than the fibers, which comprise an elastic polymer. To the agglutination and the Put together of fibers comprising an elastic polymer to avoid is it for the present invention essential that the fine fibers, the surrounded by elastic polymer fibers, made of a non-elastic Polymer are composed.

It is for the present invention requires that the microfine fiber-forming Fibers are in the following state: the fibers, which are elastic Polymer, and the fibers, which are a non-elastic polymer include, in the sea component polymer mixed together and put together and continue to be the Fibers comprising the elastic polymer and the fibers, which comprise the non-elastic polymer, in all fiber cross sections largely homogeneous without uneven distribution dispersed. This means, in side-by-side fibers, wherein fibers which are an elastic polymer and fibers comprising a non-elastic polymer, are exposed to particularly uneven distribution, or in similar fibers can the non-elastic microfine fibers (B) the elastic microfine fibers (A) are insufficient envelop so that the parts of the elastic polymer in the manufacturing step of the microfine fibers strongly agglutinate with each other. As a result can no microfibers are obtained. Thus, such fibers are in the present invention not preferred.

• 1) ein Spinnverfahren umfassend das Vermischen des nicht-elastischen Polymers, das die nicht-elastischen mikrofeinen Fasern (B) stellt, mit dem Meer-Komponenten-Polymer in einem vorgeschriebenen Mischungsverhältnis, Schmelzen des Gemischs in einem einzigen Schmelzsystem und dafür sorgen, dass dieses zusammen mit dem elastischen Polymer, das die elastischen mikrofeinen Fasern (A) stellt, in ein weiteres System fließt, wobei die Faserform durch ein Spinndüsenteil festgelegt wird,
• 2) ein Spinnverfahren umfassend das Vermischen des elastischen Polymers, das die elastischen mikrofeinen Fasern (A) stellt, mit dem Meer-Komponenten-Polymer in einem vorgeschriebenen Mischungsverhältnis, Schmelzen des Gemischs in einem einzigen Schmelzsystem und dafür sorgen, dass dieses zusammen mit dem nicht-elastischen Polymer, das die nicht-elastischen mikrofeinen Fasern (B) stellt, in ein weiteres System fließt, wobei die Faserform durch ein Spinndüsenteil festgelegt wird,
• 3) ein Spinnverfahren umfassend das Vermischen des nicht-elastischen Polymers, das die nicht-elastischen mikrofeinen Fasern (B) stellt, mit dem Meer-Komponenten-Polymer in einem vorgeschriebenen Mischungsverhältnis, Schmelzen des Gemischs in einem einzigen Schmelzsystem, Vermischen des elastischen Polymers, das die elastischen mikrofeinen Fasern (A) stellt, das in einem anderen System geschmolzen wurde, mit dem Meer-Komponente-Polymer in einem vorgeschriebenen Mischungsverhältnis, Schmelzen des Gemischs in einem einzigen Schmelzsystem und dafür sorgen, dass diese zusammen fließen, wobei die Faserform durch ein Spinndüsenteil festgelegt wird,
• 4) ein Spinnverfahren umfassend die mehrfache Wiederholung von Verknüpfung-Teilung (engl. "joint-division") am Spinnkopfteil, um ein Mischsystem der beiden auszubilden anstelle der Spinnweise in den vorstehenden Verfahren, die die Faserform durch das Spinndüsenteil definieren, oder ein ähnliches Spinnverfahren. Unter diesen Verfahren ist das vorstehende Verfahren 1) oder Verfahren 4) bevorzugt, da die in der vorliegenden Erfindung definierten mikrofeinen faserbildenden Fasern leicht erhalten werden können.

These microfine fiber-forming fibers can be obtained as follows:

• 1) A spinning process comprising mixing the non-elastic polymer constituting the non-elastic microfine fibers (B) with the sea component polymer in a prescribed mixing ratio, melting the mixture in a single melting system, and causing it to together with the elastic polymer which constitutes the elastic microfine fibers (A), flows into another system, the fiber shape being defined by a spinneret part,
• 2) a spinning process comprising mixing the elastic polymer constituting the elastic microfine fibers (A) with the sea component polymer in a prescribed mixing ratio, melting the mixture in a single melting system, and ensuring that it does not mix with the mixture elastic polymer which constitutes the non-elastic microfine fibers (B) flows into another system, the fiber shape being defined by a spinneret part,
• 3) a spinning process comprising mixing the non-elastic polymer constituting the non-elastic microfine fibers (B) with the sea component polymer in a prescribed mixing ratio, melting the mixture in a single melt system, mixing the elastic polymer, which makes the elastic microfine fibers (A) melted in another system with the sea component polymer in a prescribed mixing ratio, melting the mixture in a single melt system and causing them to flow together, the fiber form passing through a spinneret part is set,
• 4) a spinning process comprising the multiple repetition of joint-division at the spinner head part to form a mixing system of the two, instead of spinning in the above processes defining the fiber shape through the spinneret part, or a similar spinning process , Among these methods, the above method 1) or method 4) is preferable because the microfine fiber-forming fibers defined in the present invention can be easily obtained.

To microfibers without agglutination and assembly of parts of the elastic polymer during the extraction and removal of the In the present invention, it is necessary that the microfine fiber-forming fibers be prepared to have a sea component polymer such as a solvent, so as to have a structure in which the number of strands of the elastic microfine fibers (A) is 3. Is 50 and the number of strands of the non-elastic microfine fibers (B) is 15 or more in each cross section along the direction perpendicular to the fiber axis of each fiber bundle, the ratio of the number of strands (A / B) is 1/5 or less and the elastic microfine fibers (A) and the non-elastic microfine fibers (B) in the microfine fiber bundles are mixed and joined together. The structure in which the elastic microfine fibers (A) and the non-elastic microfine fibers (B) are mixed and joined indicates a state in which the elastic microfine fibers (A) and the non-elastic microfine fibers (B) in any fiber cross-sections of the bundle are substantially dispersed without a locally unequal distribution.

If the number of strands from the elastic microfine fibers (A) is more than 50, are the elastic microfine fibers (A) are too close to each other, so that agglutinating the elastic microfine fibers (A) with each other and while the extraction and removal of the sea component put together to to give a structure in which the non-elastic fibers also be included. As a result, the structure becomes too dense, so theirs Texture is hard and the mechanical properties like that tear strength deteriorate. On the other hand, if the number of strands is off the elastic polymer fibers is less than 3, exceeds the average Fineness of the elastic polymer 1 denier (1.11 dtex), so that itself the surface density and smoothness deteriorate. In addition, the elastic lies Polymer with a high fineness on the surface of the substrate open. Due to its high friction resistance intensifies the feeling a rough surface. If this is for colored Article is used, color spots of elastic polymer Visible against non-elastic polymer, so that its appearance deteriorated. When the weight fraction of the elastic polymer can be reduced, the average fineness of the elastic Polymer be reduced. In this case, however, the resulting Synthetic leather like a tea towel and has a poor texture. Preferably the number of strands from the elastic polymer fibers 5-45.

If the number of strands from the non-elastic microfine fibers (B) below 15 is the shielding of the elastic microfine fibers (A) insufficient. Thus, the elastic microfine fibers agglutinate (A) with each other and become during the extraction and removal of the sea component joined together to form a To give structure in which the non-elastic fibers also included become. In addition, the salary is in percent of non-elastic polymer preferably about 50% or more regarding procedures and practical application. Therefore, the fineness is of the industrially-made non-elastic polymer about 0.2 Denier (0.22 dtex) or more. As a result, the resulting has Product a hard texture and poor mechanical properties like the tear strength. The number of non-elastic fibers (B) is 15 or more, preferably 25 or more and stronger preferably 50 or more. The number of strands is in terms of lightness the production preferably 5000 or less.

If The relationship the number of strands the elastic microfine fibers (A) to that of the non-elastic microfine fibers (B) (A / B) greater than 1/5 is, can the non-elastic microfine fibers (B) the elastic microfine fibers (A) do not sufficiently envelop. Thus, the elastic microfine fibers (A) agglutinate with each other and will be during the extraction and removal of the sea component joined together to form a To give structure in which the non-elastic fibers also included become. As a result, the structure becomes too dense, leaving the texture Hard and mechanical properties such as tear resistance deteriorate. The relationship between the aforementioned Number of strands (A / B) is preferably 1/10 or less. The ratio is preferably 1/2000 or more in terms of ease of manufacture. The ratio of Average fineness of elastic microfine fibers (A) to that of the non-elastic microfine fibers (B) (A / B) preferably in the range between 2 and 5000 and more preferably between 5 and 500 for easy achievement of the object of the present Invention and the ease of fiber production.

It is necessary that the weight ratio of A to B (A / B) in the microfine fiber bundles be in the range of 10/90 to 60/40. When the proportion of A is more than 60/40, practical performance such as mechanical properties does not reach a sufficient level. In addition, the repellent feel and rubbery feel inherent in the elastic polymer increase. Moreover, the elastic microfine fibers (A) are too close together that the elastic microfine fibers (A) agglutinate with each other and are joined together during the extraction and removal of the sea component to give a structure in which the non-elastic Fibers are also included. Consequently, the resulting product has a hard texture and feels rubbery and repellent. Thus, the practical features deteriorate. On the other hand, if the weight ratio (A / B) is less than 10/90, microfibers are made of the elastic polymer. However, the proportion of non-elastic microfine fibers (B) that are not close to elastic microfine fibers (A) increases, so that the amount of non-elastic microfine fibers (B) which are not elastic microfine fibers ( A) bind, increases. Thus, the resulting structure becomes loose, so that no texture as in natural leather can be obtained. In addition, the fibers get pores. This causes problems with the method or practical use. The weight ratio (AB) is preferably in the range of 15/85 to 55/45.

If the average fineness of the elastic microfine fibers (A) is more than 0.5 denier (0.55 dtex), this increases the elastic polymer own repellent feeling. Furthermore, the surface density and smoothness deteriorate. Consequently It is difficult to get the result texture and appearance like natural Leather reserves. The Average fineness of elastic microfine fibers (A) is preferably 0.3 denier (0.33 dtex) or less, and more preferably 0.2 denier (0.22 dtex) or less, and is preferably 0.005 denier (0.005 denier) dtex) or more. When the average fineness of non-elastic microfine Fibers (B) over 0.2 denier (0.22 dtex) has the resulting product a hard texture. Furthermore adult problems with surface density and smoothness. Thus, it is difficult for the result to be texture and appearance like natural Leather reserves. The average fineness of non-elastic microfine Fibers (B) is preferred 0.15 denier (0.16 dtex) or less, and more preferably 0.1 denier (0.11 dtex) or less, and is preferably 0.0002 denier (0.0002 dtex) or more.

In the microfine fiber-forming fibers of the present invention means the elastic polymer that the elastic microfines Fibers (A) as an island component, any polymer whose Strain recovery rate at 1 minute after stretching of the polymer by 50% at room temperature is 50% or more. The non-elastic Polymer means any polymer whose strain recovery rate Measured in the same way for the non-elastic polymer is 50% or less, or any polymer whose limit strain rate is 50% at room temperature not reached.

Examples for the close elastic polymer Polyurethanes obtained by reacting at least one selected polymer polyol having a number average molecular weight of 500 to 3500, such as Polyester polyols, polyether polyols, polyester ether polyols, polyacetone polyols and polycarbonate polyols, with an organic diisocyanate, such as 4,4'-diphenylmethane diisocyanate, Tolylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate or Hexamethylene diisocyanate and a chain extender having two active hydrogen atoms, such as 1,4-butanediol or ethylenediamine; Elastomers on Ester base, such as polyester elastomers and polyetherester elastomers; Amide-based elastomers such as polyetheresteramide elastomers, polyesteramide elastomers; Block copolymeric polymers containing in their molecule a conjugated polymer diene-based or a diene-based conjugated polymer block such as polyisoprene or polybutadiene; and melt-spinnable Elastomers with rubber elasticity one. Above all, polyurethanes are the most preferred because of their softness and their frictional resistance are high and their rejection low is, so the effect of binding non-elastic microfine Fibers is achieved, and their heat resistance and durability are high.

The non-elastic polymer containing the non-elastic microfine Fibers (B) as an island component The task is to make the microfine fibers (A) of the elastic Separate polymers without agglutinating, and microfibers to turn them off. Therefore, a non-elastic is preferred Polymer selected, its parts under treatment with a for extraction and removal the sea component did not use solvents agglutinate. In particular, a polymer is preferred the treatment is a solvent swell rate of 10% by weight or less. Such a non-elastic polymer At least one melt-spinnable polymer is selected from melt-spinnable Polyamides such as nylon-6, nylon-66, nylon-10, nylon-11, nylon-12 and copolymers thereof, melt-spinnable polyester, such as polyethylene terephthalate, Polybuylene terephthalate and modified polyethylene terephthalate the cation-dyeable type and melt spinnable polyolefins such as polypropylene and copolymers from that. Naturally can two or more polymers are mixed and used.

On the other hand, the polymer that constitutes the sea component (the polymer that should be extracted and removed) is a polymer whose solubility or decomposability to a solvent or decomposer is different from that of the polymer as an island component (the polymer from which the sea component is high in solubility or decomposability) whose affinity for the islet polymer is small and whose surface tension is small or whose melt viscosity is lower than that of the island component in the same melt system. Step Example These include at least one melt-spinnable polymer selected from polymers which can be easily dissolved, such as polyethylene, polystyrene, modified polystyrene and ethylene-propylene copolymers, and polymers which are easily decomposed, such as sodium sulfoisophthalate-modified (copolymerized ) Polyethylene terephthalate or polyethylene glycol.

Regarding the melt spinning stability For example, a polymer having a melting point that is suitable is preferred is for the temperature at which the elastic polymer is melt spun Can be used as a non-elastic polymer and polymer that is the sea component represents, selected. For example, amount for the case where one of the polyurethanes is used as the elastic polymer is the melting points of the non-elastic polymer and the polymer, that represents the sea component, preferably 230 ° C or less. In the case, that of one of the polyester elastomers and polyamide elastomers as elastic Polymer used, the melting points of the non-elastic Polymer and the polymer that provides the sea component, preferably 260 ° C or less.

The Fineness, the number of strands and the fiber length the microfine fibers that are the island component of a flow of mixed Can provide polymers by change e.g. the combination of the mixing ratio between the non-elastic Polymer or the elastic polymer that makes up the flow, and the polymer as the sea component, its melt viscosity and / or its surface tension be adjusted. When the mixing ratio of the polymer containing the Island component increases, increased to the polymer as a sea component, generally increases Number of strands from the island component fibers. If the melt viscosity and the surface tension of the island polymer increases the following slope: the fineness increases, the number of strands the fibers sink and the fiber length decreases is shortened. On the basis of this inclination, the fineness, the number on strands and the fiber length the non-elastic polymer or the elastic polymer, the the island component provides, the mixed polymer flow in microfines fiber-forming fibers are detected by the polymer containing the Island component and the polymer that provides the sea component in the mixed polymer flow be combined accordingly and then the combination according to the actual Spinning temperature and speed is spun experimentally.

The Length of Island component fibers in the fibers obtained from the blended polymer flow is limited, wherein the non-elastic polymer or the elastic Polymer and the polymer mixed as a sea component and in one melted single melting system. However, the length is preferably 5 mm or more to using mechanical properties based on devouring microfine fibers or agglutination / entanglement with the non-elastic microfine fibers (B) and elastic microfines Fibers (A) to retain and the elongation of the base material in the process to suppress. However, it is difficult in the art to make microfine fibers of length 80 cm or more obtained by mixed spinning. The fiber length of the non-elastic polymer or the elastic polymer from the mixed polymer flow, can be changed as desired, by a combination of the non-elastic polymer or the elastic Polymer and the polymer is selected as the sea component during spinning. In the case, that one of the polymers is selected from the aforementioned Polyurethanes, polyester elastomers and polyamide elastomers as elastic polymer component is used, it is possible fibers which are excellent in melt spinning stability and sufficiently long fiber length exhibit. About that In addition, such a polymer has a high frictional resistance to the non-elastic microfine fibers (B) to ensure adequate effect to have the fiber fixation. Thus, such a case is the best case. In the case, that mixed spinning is not used but uses compound spinning is, is the fiber length the resulting microfine fibers unlimited. In the case however, that synthetic leather is made from the microfine fibers, the fibers become common cut to be used as staple fibers. Thus, exceeds the fiber length not the fiber length of staple fibers.

If necessary, the microfine fiber-forming fibers are subjected to treatment steps such as stretching, curling, heat-setting and cutting to make fibers having a fineness of 1 to 20 denier. The fineness and average fineness referred to in the present invention can be readily determined from the cross-sections of the microfine fiber-forming fibers. That is, a cross section of the microfine fiber-forming fibers is photographed with a microscope, and then the respective number of strands of the elastic microfine fibers (A) and the non-elastic microfine fibers (B) in the fiber section are counted. The respective weights of the elastic microfine fiber (A) constituting a fiber of 9000 m in length and the non-elastic microfine fiber (B) constituting the same fiber are divided by the above-mentioned respective numbers. By photographing a cross section of fiber bundles constituting a fibrous substrate in this way, it is easily possible to obtain the average fineness of elastic microfine fibers (A) and non-elastic microfine fibers (B), the number of strands thereof and the ratio between the numbers. The weight ratio between the elastic microfine fibers (A) and the non-elastic microfine fibers (B) can also be obtained by selecting any solvent having different solubility or decomposability to the elastic microfine fibers (A) and the non-elastic microfins Having fibers (B) and then only the elastic microfine fibers (A) or only the non-elastic microfine fibers (B) are removed from the fibrous substrate. It is easy to know whether the fiber length is 5 mm or more or not by making a fiber-entangled nonwoven fabric, whereby the elastic polymer and the non-elastic polymer are converted into fiber bundles, the bundle is taken out and examined with a microscope. The number of strands of the microfine fibers (A) and (B) referred to in the present invention is an average value. The ratio between the numbers is a ratio between the means of the numbers.

In In the present invention, the microfine fibers are preferable only from the elastic microfine fibers (A) and the non-elastic ones microfine fibers (B) put together. However, fibers can not within the scope of the present invention, in small quantities provided the texture and appearance of the present Invention not destroyed become. One or more stabilizers and / or colorants may be used in the fibers are incorporated.

The microfine fiber-forming fibers are opened with a card, pass through a Webber at random Webs or overlapping webs train. The resulting webs become desirable Weight and thickness laminated. The laminated webs will be then a known entangling treatment such as needles or water jet entanglement to convert the webs into nonwovens. Of course you can Time of conversion to the nonwoven fabric other microfine fibers, microfine fiber-forming fibers and / or ordinary fibers are added, provided the task of the present. Invention is not particularly destroyed. If necessary, a resin which can be dissolved away, for example a polyvinyl alcohol-based resin to which nonwoven fabric is added, for the time being to solidify.

If necessary, the fiber-entangled nonwoven fabric with a solution or an emulsion of a non-fibrous elastic polymer in a small amount waterproof and coagulated for the purpose of adapting the texture. If however, the amount of non-fibrous elastic polymer is large no texture like natural Leather can be obtained. Therefore, the amount is preferably about 10% by weight or less based on the fibrous substrate. Examples of suitable elastic polymers with which the fiber-entangled nonwoven fabric waterproof will close Polyurethane obtained by reacting at least one selected polymer diol having a number average molecular weight of 500 to 3500, such as Polyester diols, polyether diols, polyetherester diols and polycarbonate diols, with at least one diisocyanate selected from aromatic, alicyclic and aliphatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate and a low molecular weight compound with two or more active hydrogen atoms, such as ethylene glycol or Ethylenediamine in a certain molar ratio can be obtained. One such polyurethane is used as a polymer composition a polymer such as synthetic rubber or polyester elastomer optionally added. The elastic polymer like polyurethane is in a solvent solved or in a non-solvent like Water is dispersed, and then the fiber-entangled nonwoven fabric with the resulting polymer solution impregnated. The resulting product is treated with a non-solvent for the polymer, to cause wet coagulation, or it is heat treated or with hot Water treated to dry coagulation or hot water coagulation to effect. So will a fibrous Substrate obtained. One or more additives like a colorant, coagulation regulator or antioxidant can the polymer solution be added.

Next, the fibrous substrate is treated with a liquid which is a non-solvent for the non-elastic polymer, the elastic polymer and the polymer used for impregnation and which is a solvent or decomposer for the sea component of the microfine fiber-forming fibers. For example, toluene is used when the non-elastic polymer is nylon, polyethylene terephthalate or polypropylene, the elastic polymer is a polyurethane, an ester elastomer or an amide elastomer, and the sea component is polyethylene. An aqueous caustic soda solution is used when the non-elastic polymer is nylon, polyethylene terephthalate or polypropylene, the elastic polymer is a polyurethane or an amide elastomer, and the sea component is a slightly alkali-decomposable polyester. By this treatment, the polymer as a sea component is removed from the microfine fiber-forming fibers of the present invention, so that the fibers are converted into microfine fiber bundles, wherein the non-elastic microfine fibers (B) and the elastic microfine fibers (A) mixed and joined together. At the same time, the elastic polymer swells with the solvent, so that the non-elastic microfine fibers (B) are bonded in the vicinity of the elastic microfine fibers (A). As a result, soft microfine fiber bundles are obtained as in natural leather wherein both the elastic microfine fibers (A) and the non-elastic microfine fibers (B) are divided into microfibers and the microfine fibers are densely accumulated.

The Thus obtained sheet material is substantially only from the above described microfine fiber bundles composed. Therefore, the sheeting has a fibrous substrate structure like natural Leather on. As a result, the sheeting has texture and appearance like natural Leather, which is different from artificial leathers of the prior art, and can be used as a suede type or as a grained type in a variety of articles, like clothes, furniture, Shoes and bags, to be used. The sheeting of the present Invention is particularly useful for the fields high-quality grained article and high-quality suede article.

The Suede-type sheet can be obtained by roughening at least one surface of the fibrous Substrate, dyeing of the fibrous Wild-type substrate using a normal staining method using one mainly e.g. from an acid dye, a premetallized dye or a disperse dye, and optionally of the dyed fibrous Suede-type substrate of a finishing treatment such as rubbing, Softening and brushing.

Concerning the grained type on the other hand, a surface coating, which is the grained surface layer be formed as follows: (1) a transcription method, where a solution or a dispersion solution an elastic polymer such as polyurethane, optionally added a colorant can be on a detachable carrier is applied and the carrier is linked / joined together with a fiber-entangled nonwoven fabric before the applied coating loses its adhesion or the Coating is dried and the dried coating with fiber-entangled nonwoven fabric by means of a soft adhesive linked / merged; (2) a method comprising applying a solution or dispersion solution of elastic polymer such as polyurethane directly onto a fiber-entangled nonwoven fabric with a gravure roll; or (3) a coating process comprising i) Perform For example, a method for applying such a solution or dispersion solution in the manner of roller application, performing wet coagulation, Drying and dyeing the surface, around a surface coating and ii) refining the layer by embossing. If the surface finishing the grained leather on which the surface coating is formed, is insufficient, a polyurethane solution that is a colorant or no colorant contains applied to this sheeting to match color or shine. The sheeting is optionally subjected to a refining treatment like softening, dyeing or a treatment with a water-repellent substance, and will subsequently e.g. subjected to a rubbing or embossing treatment, to make a grained leather. As described above Any commonly used method can be used.

in the Below are embodiments of Present invention described by working examples. The present However, the invention is not limited to these examples. parts and percentages in the examples are by weight unless otherwise specified. The swelling rate of the non-elastic microfine fibers (B) with a extracting solvent was calculated as follows. Ingredients besides non-elastic microfine Fibers (B) were removed from the resulting artificial leather, the leaving behind non-elastic microfine fibers (B). After that, the non-elastic microfine fibers (B) at 50-100 ° C for 20 hours vacuum dried and then at a temperature at which the non-elastic Fibers (B) thermally melted by means of a press molding machine could be, to a 100 microns shaped thick film. The film was cut into squares whose Side lengths were every 10 cm, and then the weight (WO) of the square. After that, the square became for 1 hour at an extraction temperature in an extraction solvent dipped and then the solvent adhering to the surface became wiped off. The weight (W) of the resulting square was measured. The swelling rate was according to the following Calculation equation calculated. The swelling rate (% by weight) of the non-elastic microfine fibers (B) = (W - W0) × 100 / W0

example 1

A melt formed by melting 40 parts of nylon-6 [a non-elastic polymer constituting the non-elastic microfine fibers (B)] and 40 parts of polyethylene (melt index = 70) in a single system and melting 20 parts of a polyurethane polyester-based [an elastic polymer constituting the elastic microfine fibers (A)] melt formed in another system was spun in such a manner that the number of islands of the elastic polymer 25 would, with a spinning process, in which the fiber shape is determined by a spinneret part. Thus, microfine fiber-forming fibers having a fineness of 15 denier, a ratio between the number of strands (A / B) of 1/24 and a weight ratio (AB) of 33/67 were obtained. At this time, a cross-section of the fibers was considered. As a result, the average number of strands of the non-elastic microfine fibers (B) consisting of nylon-6 was about 600. The polyester-based polyurethane and nylon-6 were substantially homogeneously dispersed, and the non-elastic microfine fibers (B ) comprised of nylon-6, surrounding each of the microfine polyester-based polyurethane fibers (A). The resulting fibers were stretched 3.0 times, crimped, cut to a fiber length of 51 mm, opened with a card and formed into fabrics with an overlay webber. Next, the webs were converted with a needle device into a fiber entangled nonwoven having a basis weight of 700 g / cm ² . During these steps, the size of the fibers was reduced to about 5.9 denier (6.55 dtex). This fiber-entangled nonwoven fabric was impregnated with an aqueous polyurethane emulsion composition containing 3% of polyether-based polyurethane (the added amount of the polyurethane: 2% of the fibers after making the fibers microfine), and then thermally treated. The polyethylene in the microfine fiber-forming fibers was then extracted with toluene at 90 ° C and removed. The swelling rate of the non-elastic microfine fibers (B) with 90 ° C toluene was 1%. The sea component removal treatment resulted in a fibrous substrate about 1.3 mm thick comprising microfine fiber bundles in which the microfine polyester-based and nylon-6 polyurethane fibers (A) were mixed and joined together, and non-fibrous polyurethane (the content on weight = 2% by weight).

According to the consideration a cross section of the microfine fiber bundle of this fibrous substrate with an electron microscope was the microfine fiber (A), which comprising polyester-based polyurethane, divided into about 25 strands, and the microfine polyester-based polyurethane fibers agglutinated hardly together. About that in addition, it was found that this fiber had a structure wherein the microfine fiber (A), which is the polyester-based polyurethane and the microfine fibers (B) were mixed and joined together and they partly agglutinated and that the non-elastic microfine fibers (B) surrounded each of the microfine fibers (A). The average fineness of the microfine fibers (A), which The polyester-based polyurethane was 0.055 denier (0.055 dtex) and scarcely any scatter in fineness was observed. Including the average fineness of the microfine fibers Nylon-6 was 0.004 denier (0.004 dtex). The fiber length of the Most microfine fibers (B) comprising nylon-6 was 5 mm or more. A surface This substrate was subjected to polishing to increase the thickness 1.20 mm. After that, the other surface became a Emery polishing machine subjected to a roughened microfine fiber surface to build. The substrate was further prepared with Irgalan Red 2GL (U.S. from Chiba Geigy) with a concentration of 4% of the fiber weight colored (owf) and refined. The resulting suede artificial leather was soft and felt unsightly and rubbery. The leather also had drapability and texture like natural Leather on, was excellent in color developability and showed elegant light reflections. His appearance was also very well.

The mentioned above fibrous Substrate became a grained artificial leather in the following manner refined. As a result, the leather was soft. The leather felt also little repellent and rubbery and had a texture like natural Leather. His creasing was like natural Leather and its appearance was excellent.

The Way for the finishing to the grained artificial leather: a surface of the mentioned above fibrous Substrate was subjected to polishing to the thickness of 1.20 mm equalize. The surface was then contacted with a flat roll at 120 ° C to give a treatment to perform surface smoothing, and was subsequently coated by means of a gravure roll with a 20% polyurethane solution. Farther became the surface coated by means of a gravure roll with a 10% polyurethane solution. The polyurethane-coated surface was using a heated embossing roller shaped to to refine the substrate to the grained artificial leather. The resulting grained artificial leather possessed high quality palpability with texture and appearance like natural leather.

Example 2

The The same procedure as in Example 1 was carried out except that the nylon-6 of the non-elastic polymer by a copolymer of nylon-6 and nylon 66 was replaced to a suede-like synthetic leather too receive. The swelling rate of the non-elastic microfine fibers was 3%. The resulting suede artificial leather had a texture like natural Leather in the same way as in Example 1. The results of Viewing with an electron microscope were also the same as in example 1. His appearance was also good.

Example 3

The The same procedure as in Example 1 was carried out except that the polyester-based polyurethane of the elastic polymer and the nylon 6 of the non-elastic polymer each with an elastomer polyether-based and modified with 10 mol% isophthalic acid Polyethylene terephthalate were replaced, and a disperse dye as a dye was used to a suede-like artificial leather to obtain. The swelling rate of the non-elastic fibers was 7%. The resulting suede artificial leather had a texture like natural Leather in the same way as in example 1. Its appearance was good too.

Comparative Example 1

The The same procedure as in Example 1 was carried out except that the spinning process in which the fiber shape through the spinneret part was replaced by a spinning process in which Linking / sharing on a spinnwärmeteil was repeated to form a mixture of the two, and the 25th Islands of the elastic polymer have been replaced by 10 islands thereof to get a suede-like artificial leather. According to the consideration a portion of the microfine fiber bundle with an electron microscope was expected to increase the number of islands of the polyurethane Polyester base is 100, but the polyester-based polyurethane fibers adhered and agglutinated with each other to assemble. The nylon 6 fibers were included therein. The resulting suede leather was tougher and harder showed a more papery compared to that of Example 1 Texture and poorer Light reflections on the surface and a poorer one Appearance on.

Comparative Example 2

The The same procedure as in Example 1 was carried out except that the melt index of polyethylene has been changed from 70 to 120, the number of islands of nylon-6 has been changed from 600 to 100, the number of strands from the polyester-based polyurethane was changed to 40 and the ratio between the numbers of strands of 1/24 changed to 1 / 2.5 was to get a suede-like artificial leather. According to the consideration a cross section of the microfine fiber bundle with a microscope expects the ratio the number of strands between the polyester-based polyurethane and nylon-6 is 1 / 2.5, but the polyester-based polyurethane fibers agglutinated with each other, to be joined together become. The nylon 6 fibers were included therein. Thus was it is not possible the numbers of strands and the relationship between the numbers of strands to count. The resulting suede-like artificial leather was tougher and harder showed a more papery compared to that of Example 1 Texture and poorer Light reflections on the surface and a poorer one Appearance on.

Comparative Example 3

The The same procedure as in Example 1 was carried out except that the weight ratio polyester-based polyurethane to Nylon-6 from 33/67 to 5/95 changed was to get a suede-like artificial leather. According to the consideration a cross section of the microfine fiber bundle with an electron microscope The polyester-based polyurethane was made of microfibres, but the microfine fibers comprising nylon-6 were hardly affected by the microfines Fibers comprising the polyester-based polyurethane are bonded. His Structure was loose. The resulting suede-like artificial leather owned one more paper-like texture than that of Example 1. Much of the Surface roughening was lost. His appearance was poor.

Comparative Example 4

The The same procedure as in Example 1 was carried out except that the weight ratio of the polyester-based polyurethane to nylon-6 from 33/67 to 80/20 changed was to get a suede-like artificial leather. According to the consideration a cross section of the microfine fiber bundle with an electron microscope the polyester-based polyurethane fibers agglutinated with each other, to put together to become. The nylon 6 fibers were included in it. The resulting suede-like artificial leather was harder and felt Compared to that in Example 1 more repellent and rubbery at. This leather also had weaker ones Surface light reflections and a poorer one Appearance on.

Comparative Example 5

The same procedure as in Example 1 was carried out except that the number of islands of the polyester-based polyurethane was set to 1 instead of 25 to obtain a suede-like synthetic leather. According to the observation of a cross section of the microfine fiber bundle with an electron microscope, the bundle had a structure in which a strand of the polyester-based polyurethane fiber having an average fineness of 1.5 denier (1.66 dtex) and the nylon 6 fibers were mixed together and joined together , The resulting suede-like artificial leather exhibited a texture that was more repellent than the synthetic leather of Example 1, with white, eye-catching roughening in its surface and gave a rough feeling and poor appearance and surface feel.

Comparative Example 6

The The same procedure as in Example 1 was carried out except that the spinning process in which the fiber shape through the spinneret part is set in a way that the number of islands the elastic polymer 25 would be was replaced by a spinning process in which a spinneret with a Structure from the side-by-side kind was used, and the 25 islands of the elastic polymer were by a single pre-embossed Soul replaces to get a suede-like artificial leather. According to the consideration a cross section of the microfine fiber bundle with an electron microscope adhered parts unevenly distribute polyester-based polyurethane to each other and a part of the nylon 6 fibers were included therein. The resulting suede-like artificial leather was tougher and harder showed a more papery compared to that of Example 1 Texture and poorer Surface reflections and a poorer appearance on.

Effect of the present invention

The Fibrous substrate for artificial leather obtained by the present invention has a texture and appearance like natural leather. Thus is the substrate as a suede type or as a grained type for a variety of articles for clothes, Furniture, Shoes, bags and the like usable. The fibrous Substrate for Artificial leather of the present invention is particularly useful in the field of high-quality grained articles and high-quality suede-like Articles that were previously exclusive from natural Leather could be obtained.

Claims (7)

fibrous Substrate for Artificial leather, comprising microfine fiber bundles, each of which consists of 3 to 50 pieces microfine fibers (A) comprising an elastic polymer and an average fineness of 0.5 denier (0.55 dtex) or having less and 15 or more pieces of microfine fibers (B), which comprise a non-elastic polymer and an average Have fineness of 0.2 denier (0.22 dtex) or less, composed wherein the microfine fiber bundles have the following conditions (1) to meet (3): (1) The relationship the number of strands from A to the number of strands from B in cross sections of the bundles (A / B) is 1/5 or less, (2) the ratio of the weight of A to Weight of B in the bundles (AB) is 10/90 to 60/40, and (3) the microfine fibers (B) containing the include non-elastic polymer, enclose each of the microfine fibers (A) comprising the elastic polymer. fibrous Substrate for An artificial leather according to claim 1, wherein the ratio of the fineness of the microfine Fibers (A) to that of microfine fibers (B) (A / B) in the range of 2 to 5000 lies. fibrous Substrate for Artificial leather according to claim 1 or 2, wherein the elastic polymer a polyurethane is. fibrous Substrate for Synthetic leather according to one of the claims 1 to 3, wherein the non-elastic polymer is at least one of polyamides, Polyesters and polyolefins is selected polymer. fibrous Substrate for Synthetic leather according to one of the claims 1 to 4, wherein the fibrous substrate with the elastic polymer in an amount of 10% or less based on the weight of the microfine fibers that make up the substrate form, soaked. Suede leather, available by roughening at least a surface The substrate according to any one of claims 1 to 5. Imitation leather with a grained surface layer, available by coating at least one surface The substrate according to any one of claims 1 to 5, comprising a resin layer.